Photochromics represent a fairly common technology in which the active material, typically incorporated into the lenses of eyeglasses, darkens in the presence of intense light and lightens in its absence. For instance, photochromic-based lenses commonly darken when exposed to bright sunlight and then lighten when the lenses are brought indoors. Drawbacks of photochromics include poor switching speed, high cost, and weight. Moreover, photochromic lenses often fail to operate or “switch” indoors, or in automobiles, because they require UV light in order to activate or switch.
As an alternative to photochromic materials, electrochromic materials provide a color change in response to an applied voltage. However, electrochromic materials have not found commercial success as a replacement for photochromics.
Accordingly, there is a need in the field for lenses and eyewear that may include materials, such as electrochronic materials, that may be wearable by a user with improved light/dark switching speeds and operate in a variety of conditions and environments.